Cats can suffer anemia for several reasons, one beeing Pyruvate kinase defficiency PK-def. There are now plenty of scientific articles showing that PK deficiency is a large problem within the Abyssinian and Somali breed (see below for references). Read about the PK deficiency test at VGL at UC Davis
Fortunately there is a DNA test available for this autosomal recessive trait, which means that this problem is easily controlled in future litters, provided that the parents are tested and carriers are only mated to normal cats with respect to the mutation that gives pyruvate kinase deficiency.
In a European study there was a DNA screening for the mutation in addition to the clinical study of 25 affected cats (Kohn 2008). Of 502 Abyssinian and Somali cats 7.4 % were homozygous affected, 23.3 % were heterozygous carriers and 69.3 % normal. In the Australian study (Barrs et al 2008), 5 % were homozygous affected, 28 % were heterozygous carriers and 67 % normal. In the latter study personal communication from Prof. Urs Giger is cited were he states that the 3000 cats that have been screened at PennGen laboratory have similar percentages of carrier and affected cats.
If you assume that number of affected cats are similar in Sweden, there should be approximately 250 affected Abssinian/Somali cats in Sweden, based on number of Sverak registered Aby/Somali cats in Sweden 1995-2008. If the percentages really are similar in Sweden as compared to the rest of the world, a number of these cats most probably have already died from this disease. However, there should also be a number of affected cats that could benefit from treatment if they were correctly diagnosed. I strongly recommend any owner an Aby/Somali cat with unknown genetic status with respect to this disease to DNA test their beloved pets.
Barrs, V., U. Giger, B. Wilson, C. Chan, A. Lingard, L. Tran, A. Seng, P. Canfield and J. Beatty (2009). "Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats". Aust Vet J 87(1-2): 39-44.
Objective To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia. Design Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats. Results A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64-390 x 10(9)/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood. Conclusions The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended. [on SciFinder (R)]
Kohn, B. and C. Fumi (2008). "Clinical course of pyruvate kinase deficiency in Abyssinian and Somali cats". J Feline Med Surg 10(2): 145-53.
The objective of this study was to examine clinical signs, laboratory parameters, and course of disease in Abyssinian and Somali cats with pyruvate kinase (PK) deficiency. The clinical course of 25 PK-deficient cats was followed over a time period of 0.8-11.3 years (median 4.3). Eleven cats (age 0.8-7.8 years, median 4.4) did not show signs according to the owners. In 14 cats (age 0.1-5 years, median 1.7) the owners noted lethargy (10), diarrhoea (seven), pale mucous membranes (six), inappetence (six), poor coat quality (six), weight loss (four), icterus (four), and pica (two). Sixteen cats had been used for breeding at least once before diagnosis. Laboratory abnormalities included anaemia (70%), increased aggregated reticulocyte counts (94%), hyperglobulinaemia (80%), hyperbilirubinaemia (53%), and increased liver enzymes (47%). Six of 25 affected cats died (four) or were euthanased (two) at ages ranging from 1.3 to 11.3 years (median 4.1) presumably because of PK-deficiency. These findings emphasise that PK deficiency shows variation in age of onset and severity of signs. As PK-deficient cats can be asymptomatic testing for PK deficiency before breeding is strongly recommended. [on SciFinder (R)]
van Geffen, C., K. Savary-Bataille, K. Chiers, U. Giger and S. Daminet (2008). Bilirubin cholelithiasis and haemosiderosis in an anaemic pyruvate kinase-deficient Somali cat. England: United Kingdom, Department of Medicine and Clinical Biology of Small Animals, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium: 479-82.
A Somali cat was presented with recurrent anorexia, lethargy, vomiting and icterus. A macrocytic-hypochromic, regenerative haemolytic anaemia was identified and hereditary pyruvate kinase deficiency was confirmed by means of breed-specific DNA mutation analysis. The case was complicated by the presence of markedly elevated serum liver enzyme activities, hyperbilirubinaemia, coagulopathy and ultrasonographic evidence of gall bladder choleliths and extrahepatic bile duct obstruction. The choleliths consisted of 100 per cent bilirubin, likely because of chronic haemolysis and haeme degradation. In conclusion, haemosiderosis and bilirubin cholelithiasis can be a consequence of chronic haemolysis in pyruvate kinase-deficient cats, as seen in human beings with a variety of chronic haemolytic disorders. [on SciFinder (R)]
Aisaki, K.-i., S. Aizawa, H. Fujii, J. Kanno and H. Kanno (2007). "Glycolytic inhibition by mutation of pyruvate kinase gene increases oxidative stress and causes apoptosis of a pyruvate kinase deficient cell line". Exp. Hematol. (N. Y., NY, U. S.) 35(8): 1190-1200.
Objective: SLC3 is a Friend erythroleukemic cell line established from the Pk-1slc mouse, a mouse model of red blood cell type-pyruvate kinase (R-PK) deficiency. This study was aimed to elucidate the mechanisms attributing to apoptosis induced by R-PK deficiency. Materials and Methods: SLC3 and a control Friend cell line, CBA2, were cultured in a condition of glucose deprivation or supplementation with 2-deoxyglucose, and apoptosis was detected by annexin V. We established two stable transfectants of SLC3 cells with human R-PK cDNA, and examd. the effect of R-PK on an apoptotic feature by cell cycle anal. Intracellular oxidn. was measured with 2',7'-dichlorofluorescin diacetate. DNA microarray anal. was performed to examine gene-expression profiles between the two transfectants and parental SLC3. Results: SLC3 was more susceptible than CBA2 to apoptosis induced by glycolytic inhibition. The forced expression of R-PK significantly decreased cells at the sub G0/G1 stage in an expression-level dependent manner. Microarray anal. showed that proapoptotic genes, such as Bad, Bnip3, and Bnip3l, were downregulated in the transfectants. In addn., peroxiredoxin 1 (Prdx1) and other antioxidant genes, such as Cat, Txnrd1, and Glrx1 were also downregulated. A significant decrease of dichlorofluorescein fluorescence was obsd. by R-PK expression. Preincubation with a glutathione precursor showed a significant decrease of apoptosis. Conclusion: These results indicated that glycolytic inhibition by R-PK gene mutation augmented oxidative stress in the Friend erythroleukemia cell, leading to activation of hypoxia-inducible factor-1 as well as downstream proapoptotic gene expression. Thus, R-PK plays an important role as an antioxidant during erythroid differentiation. [on SciFinder (R)]
Chajut, A. and E. Pinner (2007). Double-stranded RNAs and their use for downregulating genes and treating cardiovascular diseases. Application: WO
WO, (Quark Biotech, Inc., USA).145pp.
The invention relates to a double-stranded compd., such as siRNAs, which down-regulates the expression of one or more cardiovascular-related gene. The invention also relates to a pharmaceutical compn. comprising the compd., or a vector capable of expressing the oligoribonucleotide compd., and a pharmaceutically acceptable carrier. The present invention also contemplates a method of treating a patient suffering from a cardiovascular disorder or other diseases comprising administering to the patient the pharmaceutical compn. in a therapeutically ED so as to thereby treat the patient. [on SciFinder (R)]
Harvey Andrea, M., E. Holt Peter, J. Barr Frances, F. Rizzo and S. Tasker (2007). Treatment and long-term follow-up of extrahepatic biliary obstruction with bilirubin cholelithiasis in a Somali cat with pyruvate kinase deficiency. England: United Kingdom, Department of Clinical Veterinary Science, Division of Companion Animals, University of Bristol, Langford, Bristol BS405DU, UK.: 424-31.
A 2-year-old female neutered Somali cat was presented with vomiting and acute onset jaundice 1 year after diagnosis of pyruvate kinase (PK) deficiency. Diagnostic investigations revealed a moderate regenerative haemolytic anaemia, severe hyperbilirubinaemia and elevated liver enzymes. Ultrasonography revealed marked distension of the gall bladder and common bile duct (CBD), consistent with extrahepatic biliary obstruction (EHBO). At cholecystotomy, the gall bladder contained purulent material, and two obstructive choleliths were removed from the CBD by choledochotomy. The cat recovered from surgery uneventfully, and serum liver enzymes and bilirubin normalised within 10 days. Postoperative treatment consisted of cephalexin, metronidazole and ursodeoxycholic acid (UDCA). Bacterial culture of the gall bladder contents yielded a pure growth of an Actinomyces species. Cholelith analysis revealed that they consisted of 100% bilirubin. Antibiotic treatment was stopped 4 weeks after surgery but UDCA was continued indefinitely. The cat remains clinically well with no recurrence of cholelithiasis 20 months after initial presentation. This is the first report of successful treatment and long-term follow-up of a cat with EHBO due to bilirubin cholelithiasis in association with PK deficiency-induced chronic haemolysis. [on SciFinder (R)]
Harvey John, W. (2006). "Pathogenesis, laboratory diagnosis, and clinical implications of erythrocyte enzyme deficiencies in dogs, cats, and horses". Vet Clin Pathol 35(2): 144-56.
Deficiencies of enzymes involved in erythrocyte metabolism can have significant effects on erythrocyte function and survival. Animals with pyruvate kinase (PK) or phosphofructokinase (PFK) deficiencies have shortened erythrocyte life spans and regenerative anemia. PK-deficient dogs (but not PK-deficient cats) develop progressive myelofibrosis and osteosclerosis of bone marrow and hemochromatosis and cirrhosis of the liver. PFK-deficient dogs have sporadic episodes of hyperventilation-induced intravascular hemolysis and hemoglobinuria. Cytochrome b5 reductase (Cb5R) deficiency in dogs and cats results in persistent methemoglobinemia and cyanotic mucous membranes. Severe deficiency of glucose-6-phosphate dehydrogenase, the rate-controlling enzyme in the pentose phosphate pathway, resulted in anemia with eccentrocytosis in an American saddlebred colt. Horses with erythrocyte flavin adenine dinucleotide (FAD) deficiency have both eccentrocytosis (attributable to severe deficiency in glutathione reductase activity) and methemoglobinemia (attributable to Cb5R deficiency); the dual enzyme deficiency occurs because FAD is a required cofactor for both enzymes. Erythrocyte enzyme deficiencies do not usually shorten life expectancy, except for PK-deficient dogs and potentially PFK-deficient dogs during a hemolytic crisis. Although enzyme deficiencies are rare causes of anemia and methemoglobinemia, the ability to diagnose deficient animals allows for the possibility of eliminating these undesirable traits in future breeding. DNA-based assays are available for PK and PFK deficiencies; whereas, biochemical tests of enzyme activity are required for other deficiencies. Continued research is needed to document additional enzyme deficiencies that likely occur and to develop additional DNA-based assays to detect heterozygous animals. [on SciFinder (R)]
Mansfield, C. S. and P. Clark (2005). Pyruvate kinase deficiency in a Somali cat in Australia. Australia, School of Veterinary and Biomedical Sciences, Division of Health Sciences, Murdoch University, South Street, Murdoch Western Australia 6150: 483-5.
A 7-year-old neutered male Somali cat, bred in Western Australia, was presented for investigation of jaundice and severe anaemia. Splenomegaly and hepatomegaly were evident on physical examination. Severe anaemia, along with leukopenia and increased liver enzymes, were present on laboratory evaluation. Clinical investigation identified cholangitis and treatment for this resolved the jaundice but failed to resolve the anaemia. Treatment for Mycoplamsa haemofelis was administered concurrently. Genetic testing was then performed and pyruvate kinase deficiency was identified, the first time this has been reported in an Australian cat. Treatment with immunosuppressive medication was not successful. [on SciFinder (R)]
Kohn, B., M. H. Goldschmidt, A. E. Hohenhaus and U. Giger (2000). "Anemia, splenomegaly, and increased osmotic fragility of erythrocytes in Abyssinian and Somali cats". J Am Vet Med Assoc FIELD Full Journal Title:Journal of the American Veterinary Medical Association 217(10): 1483-91.
OBJECTIVE: To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and Somali cats. DESIGN: Case series. ANIMALS: 13 Abyssinian and 5 Somali cats. PROCEDURES: History, pedigree information, and results of routine laboratory tests, special erythrocyte studies, and histologic evaluation of splenic and hepatic specimens were analyzed. RESULTS: Age at which clinical signs of anemia were first apparent ranged from 6 months to 5 years. Ten cats had splenomegaly. Most often, the PCV was between 15 and 25%, but it was as low as 5% at some times. The anemia was characterized by macrocytosis and mild to moderate reticulocytosis, but no poikilocytosis. Hyperglobulinemia, lymphocytosis, mild hyperbilirubinemia, and high hepatic enzyme activities were common findings. Results of Coombs tests and tests for infectious diseases were negative. The erythrocytic osmotic fragility was high in affected cats (mean osmotic fragility, 0.66 to 0.78%), compared with healthy cats (0.48 to 0.58). No specific membrane protein abnormality, erythrocyte enzyme deficiency, or hemoglobinopathy was identified. Histologic evaluation of splenic and hepatic specimens revealed extramedullary hematopoiesis and hemosiderosis. Four of the 5 Somali cats were closely related. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of results of pedigree analyses, the apparent breed predilection, and the exclusion of other known causes of anemia in cats, we believe that the hemolytic anemia in these cats was likely a result of a novel hereditary erythrocyte defect. A genetic predisposition to immune-mediated destruction of erythrocytes could not be ruled out. [on SciFinder (R)]